Padlocks are known, for example, from the U.S. Pat. Nos. 5,377,511 and 5,363,678 which are commonly-owned by the applicant. As such the contents of these particular US patents are herewith included in their entirety into the disclosure of the present invention.
A padlock in accordance with U.S. Pat. No. 5,377,511 is characterized in that the shackle can be removed completely from the lock body in a simple manner and can be replaced by another shackle. It is thus possible with such a padlock to change the length of the shackle, its shape and/or its material by such a replacement.
This shackle replacement feature is made possible in that the pin, made as a ball pin, has an additional groove whose depth has a larger dimension than the depth of its two other grooves. These two other grooves only enable movement of the locking elements, made as locking balls, into such a position in which the padlock can be opened, but the shackle cannot be completely removed from the lock body. However, engagement of one of the locking balls into the additional, deeper groove makes it possible with an open padlock that the shackle can be moved out of the lock body and can be replaced by another shackle. To cause the locking ball to engage this additional groove, it is necessary to “overrotate” the ball pin in the opening direction. Such an overrotating can be effected by means of a simple screwdriver after the lock cylinder has been removed from the lock body and the ball pin has thus been made freely accessible.
The possibility of overrotating the ball pin may, however, naturally not be given with an inserted lock cylinder since the ball pin could otherwise also be overrotated in normal practical use in a manner such that the shackle is released from the lock body. To prevent such an overrotating of the ball pin in normal practical operation, a special lock cylinder is used in the padlock disclosed in U.S. Pat. No. 5,377,511 which has an abutment element configured to restrict rotational movement of the lock cylinder core. Since such rotational movement of the lock cylinder core is only possible with restrictions, the ball pin can also only be rotated between its normal open and closed positions by means of the lock cylinder core, with over-rotation of the ball pin being prevented by the abutment element on the lock cylinder. Such an overrotating is only possible when the lock cylinder had previously been removed from the lock body.
One possible disadvantage with a padlock in accordance with U.S. Pat. No. 5,377,511 is that, upon removal of the lock cylinder from the lock body, the ball pin and possibly also the spring biasing the ball pin may unintentionally fall out of the lock body so that it is difficult for the user of the padlock who has not had special training to put the named parts back together again correctly. The insertion of the spring back into the lock body in particular may cause problems.
Another possible disadvantage is that only lock cylinders with an abutment feature can be used so that a replacement of lock cylinders is only possible with restrictions.
Padlocks similar to that disclosed in U.S. Pat. No. 5,377,511 typically have lock cylinders which are designed such that a key with which the cylinder core in the lock cylinder can be rotated can only be withdrawn from the lock cylinder in a single, defined angular position (withdrawal position) of the key. In this respect, a distinction is made between the following two types of padlocks.
In padlocks with “forced locking”, the key can only be rotated into its withdrawal position and withdrawn from the lock cylinder when the padlock is in its closed position, that is when both shanks of the shackle are locked in the lock body. If therefore no key is inserted into the lock cylinder of such a padlock, it can definitely be assumed that the padlock is in its closed state.
Padlocks with an “automatic operation”, in contrast, also allow rotation of the key to its withdrawal position and withdrawal of the key from the lock cylinder when the padlock is open, that is when the shanks of the shackle are not locked in the lock body. With such padlocks, withdrawal of the key from the lock cylinder is therefore possible, on the one hand, when the padlock is open and, on the other hand, when the padlock is locked.
Padlocks with an automatic operation are furthermore characterized in that they can be locked without a key present in the lock cylinder in that the shackle is very simply pushed into the lock body. Due to the previously mentioned bias applied to the ball pin, it is moved into its locked position subsequent to such a shackle movement so that the shackle moved into the lock body is also locked therein by its two shanks.
To enable the potential use of padlocks which are as versatile as possible, it is known to provide padlocks which can be selectively used with either forced locking or an automatic operation. Such a padlock is described in the already named and commonly-owned U.S. Pat. No. 5,363,678.
It is important in such a padlock that there is “play” between an engagement element of the pin, also made as a ball pin in this case, and an entrainer formation on the cylinder core which allows a rotation of the cylinder core through a specific angle, which can amount to approximately 60 degrees for example, without the ball pin also rotating. It is achieved by this play that the ball pin can also remain in its open position without locking the shackle in the lock body with an open padlock when the key is rotated into its withdrawal position and is subsequently removed from the lock cylinder. Only a movement of the shackle into the lock body then causes the ball pin to move into its locked position due to the mentioned bias, in which the locking elements, also made as locking balls here, lock the shackle with its two shanks in the lock body.
By insertion of a bridge member into the region between the engagement element on the ball pin and the entrainer formation on the lock cylinder core, the named play can be eliminated as required so that a rotational movement of the lock cylinder core is only possible in concert with a rotational movement of the ball pin. In padlocks with an inserted bridge member, the key can accordingly only be rotated into its withdrawal position and be withdrawn from the lock cylinder when the shackle is in the lock body and its two shanks are locked via the locking balls. If desired, it is possible to remove the bridge member from the padlock so that the named play is again present between the engagement element and the entrainer formation. It is thus possible by the selective insertion or removal of the bridge member to switch padlocks of the type shown in U.S. Pat. No. 5,363,678 between forced locking and automatic operation.
With a padlock known from U.S. Pat. No. 5,363,678, the bridge member can be removed after the lock cylinder has been removed from the lock body. After removal of the lock body, the bridge member is still typically located in the region of the engagement element on the ball pin, with it frequently occurring that the bridge member adheres to the end face of the ball pin due to adhesive forces which are, for example, amplified by the presence of lubricants so that the bridge member cannot be released from the ball pin simply due to gravity. In these cases, it is frequently attempted to release the bridge member from the ball pin by means of a screwdriver or by pounding the padlock against a hard surface in order to remove it from the padlock. However, this contains the risk that not only the bridge member, but also the ball pin and where applicable the biasing spring are unintentionally released from the lock body. As already mentioned, this is undesirable since the spring can only be inserted again with a relatively large effort, in some cases only by specially trained personnel using special tools.
It is therefore generally problematic in padlocks of the type known in the prior art that, upon release of the lock cylinder from the lock body, the ball pin and/or the biasing spring can unintentionally fall out of the lock body. In this respect, the requirement to release the lock cylinder from the lock body can, for example, be due to the fact that the lock cylinder has to be replaced, that the shackle of the padlock has to be replaced or that the padlock has to be converted between forced locking and an automatic operation.